Apparatus for the control of highway crossing signals



Oct. 3, 1939. P. H. CRAGO 2,174,621

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Original Filed April 30, 1938 INVENTOR -Paal mgo.

HIS ATTORNEY Patented Oct. 3, 1939 UNITE STTES ATENT OFFICE APPARATUS FOR. THE QDN'IROL OF HIGH- WAY CROSSING SIGNALS Original application April 30, 1938, Serial No.

Divided and this application February 23, 15539, Serial No, 257,325

3 Claims.

My invention relates to apparatus for the control of highway crossing signals, and more ticularly to apparatus for the control of highway crossing signals for electric railways.

The present application is a division of my copending application Serial No. 205,301 filed April 30, 1938, for Apparatus for the control of high-- way crossing signals.

A feature of my invention is the provision of novel and improved highway crossing signal control apparatus wherewith a loss of protection due to a temporary failure of power is avoided. Other features and advantages of my invention will appear as the specification progresses.

I shall describe one form of apparatus ernbodying my invention, and shall then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view of a preferred form of apparatus embodying my invention.

Referring to the drawing, the reference characters la and Eb designate the track rails of a stretch of single track electric railway which is provided with a propulsion current supply conductor 2, such as a trolley wire or third rail, adaptable to contact by a suitable train carried current collecting device, such as a trolley wheel or third rail shoe not shown. In accordance with usual practice, the conductor 2, when a trolley wire, is supported substantially above the center line of the track at the necessary height. To aid in describing my invention, I shall assume the conductor 2 to be the usual trolley wire. In the drawing, the conductor 2 is illustrated at one side of the track rails for the sake of clarity. It will also be understood, of course, that conductor 12 is connected with one terminal of a source of propulsion current, such as a generator not shown, and the track rails serve as the return path for the propulsion current.

This stretch of railway is intersected by a highway H, adjacent which a highway crossing signal S is located. The type of highway crossing sig nal is immaterial, and as here provided the signal S comprises a green light G and two red lights R and IR, the green light G being normally illuminated to indicate a clear signal when no railway trafiic is approaching the intersection, and the red lights R and HR being alternately and periodically illuminated to indicate stop to highway users when a train or car is approaching the intersection on the railway. The signal S is positioned to be displayed to highway trafiic approaching the intersection from one direction. In practicing my invention, a second signal sim- (Cl. Zed-4.25)

ilar to signal S would be located at the intersection and positioned to be displayed to highway traffic approaching the intersection from the other direction. This second signal is not shown for the sake of simplicity since its control would be the same as that of signal S, the control of signal S being fully described hereinafter.

Three traflic governed devices or contactors are associated with this stretch of railway at selected points. These contactors are preferably similar, and in this instance their construction is that of standard practice for trolley contactors. As viewed in the drawing, the contactors Cl and C2 positioned at selected points to the left and right, respectively, of the intersection. The distance the contactors Cl and C2 are located from the highway is in each case such as to provide satisfactory warning operation of the signal S in response to railway traffic approaching the intersection in the respective directions. To discontinue the operation of signal S, a contact C5 is positioned adjacent the intersection. In other words, a car approaching the intersection from the left, as viewed in the drawing, initiates the warning operation of signal S in passing the contactor Cl, and the warning operation is discontinued when the car passes over the highway and operates the contactor C5. A car approaching the intersection from the right initiates the warning operation of the signal in passing the contactor C2, and the warning operation is dis continued when the car passes over the intersection and operates the contactor C5.

Looking at contactor CI, for example, it comprises two contact members 3 and 9 which are juxtapositioned with contact member 3 more remote from the intersection. The contact members 3 and 9 are each spaced from the conductor 2 to be normally free from contact therewith. A trolley wheel of a car or vehicle bridges between the conductor 2 and the members 3 and 9 so that current from conductor 2 is applied to the members, current being applied first to member 3 and then to member 9 when a car approaches the intersection, the trolley wheel engaging the member 9 before it leaves the member 3. For a car receding from the intersection, that is, moving from right to left in the drawing, current is first applied'to member 9 and then to member 3 of the contactor Cl. In a similar manner, the contactor C2 comprises two juxtapositioned contact members 5 and H, the member 5 being more remote from the intersection so that a trolley wheel of a car approaching the intersection applies current first to member 5 and then to member II, but a car receding from the intersection causes current to be applied first to member I I and then to member 5.

The contactor C5 which is preferably located at the intersection is provided with a single contact member 69 to which current is applied from trolley wire 2 when the trolley wheel of a car moving over the intersection in either direction engages the contact member 69.

It will be understood, of course, that my invention is not limited to trolley contactors. The important feature of these contactors so far as my present invention is concerned is the fact that contactors CI and 02 each comprises two contact members to which current is supplied successively and momentarily in response to a car passing thereover, the order in which current is supplied to the two contact members being in accordance with the direction of the passing car. For example, in railways other than electric railways, the contact members 3 and 9 of contactor CI could be actuated by the leading wheel of a passing train, and the source of current could be any suitable wayside source.

To distinguish between cars approaching the intersection and cars receding from the intersection, a directional device is associated with the first and second contactors CI and C2. The directional device may take different forms, several being well known. As here provided the directional device comprises a slow releasing neutral relay NS controlled over a pick-up and. a stick circuit, which circuits will be described hereinafter.

The immediate control of signal S is effected by a polarized relay HR, which relay is in turn controlled by the contactors CI, C2 and C5 together with the directional relay NB, relay HR being energized at one polarity when a train is approaching the intersection and being energized at the opposite polarity when the train is receding from the intersection. The relay HR is provided with a normal energizing winding NW and a reverse energizing winding RW, the arrangement being such that when current is supplied to the normal winding NW the polar contact members. 96, I03 and I05 of the relay are operated to the left-hand position, that is, the position illustrated in the drawing, contact member I05 making engagement with a normal polar contact I06. When current is supplied to the reverse winding RW, the relay HR is energized to move its polar contact members to the righthand position, where contact members 95 and I 93. engage reverse polar contacts 9l'and I 94, respectively. The polarized relay HR is preferably characterized by the fact that the stroke of its polar armature will be completed if energy is applied to either winding for a long enough interval to open the polar contacts in the last position. In other words, when an impulse of current is supplied to winding RW or NW for an interval long enough to move the polar armature from its last position, the polar armature moves to its other extreme position although the energizing current ceases.

A relay which may be made to operate in the manner just described is disclosed and claimed in Letters Patent of the United States No. 1,790,671 granted to Branko Lazich on February 3, 1931, for Electrical relays. In the instant application the polarized relay is provided with two windings disposed for reversibly energizing the relay to operate the polar armature whereas in the patent the relay is shown provided with a single winding to which current is reversibly supplied for operating the polar armature, such equivalent arrangements for the windings of polarized relays being readily understood by those skilled in the art.

The control circuits for relay HR will be described when the operation of the apparatus is explained.

The lamp G of signal S is controlled over a back neutral contact of relay HR, and the lamps R and IR of signal S are controlled over front neutral contacts of relay HR through the medium of a flasher relay FR, which flasher relay may be of any of the well-known constructions. It is deemed sufiicient for this application to point out that the contact member 56 of relay FR is biased to a mid position, that is, the position illustrated by the solid line in the drawing, and is operated between two extreme positions, illustrated by dotted lines, at a predetermined frequency of, say, 30 times per minute when the winding of the relay FR is energized: As here shown, the contact member 56 engages a contact 5'! at both its mid and left-hand positions and engages a contact 58 at its right-hand position. For illuminating the lamp G, current is supplied from conductor 2 over wire 92, back neutral contact 93 of relay HR, a resistor R6, lamp G, wires and I0, and to the rail lb. With relay HR picked up, closing its front neutral contacts, current is supplied from conductor 2 over wire 92, front neutral contacts 98, 99, I00 and MI in series, wire 63, a resistor R1, winding of flasher relay FR, wires I4 and I9, and to track rail Ib, and the flasher relay FR is operated.

During each interval, the contact 565I of flasher relay FR is closed, the lamp IR is short-circuited, and the lamp R is illuminated by current flowing over the same circuit traced for relay FR up to wire 63, and thence over a resistor R8, contact 56-57, wire 64, lamp R and wires 55 and I0 to the track rail lb. During each interval the contact 56-58 of relay FR is closed, the lamp R is short-circuited and the lamp IR is illuminated by current flowing over the same circuit up to wire 63 and from wire 63 over resistor R8, wire 65, lamp I-R, wire 64, contact 56-58, wires I4 and T9, and to the rail II).

In describing the operation of the apparatus, I shall consider the operating steps effected in response to a car moving from left to right. At the start, the lamp G of signal S is illuminated by current supplied over the back contact 93 of relay HR. The trolley wheel of acar approaching the intersection from the left first engages the contact member 3 of contactor CI to apply current from conductor 2 to member 3, andin so doing causes current to be supplied to the reverse winding RW of relay HR, the circuit involved including contact member 3, wires 4 and I 5, back contact 94 of relay N6, wire 95, reverse winding RW, a resistor RM, wire 10, and track rail Ib. I have found that by proportioning the resistor R14 and the winding RW so that the relay HR receives only its normal ampere-turn energization the time constant of the circuit is relatively low and operation of the polar armature of relay HR in less than 0.05 second is effected. With theparts thus proportioned, the relay HR is energized to reverse its polar armature although the Winding RW is energized but for the brief interval the contact member 3 is bridged by the trolley wheel. It will be recalled that relay HR is characterized by the fact that its polar armature once started from its lastposition, will move. to

its other extreme position notwithstanding the energizing current ceases. With relay HR reversed, current is supplied over a holding circuit which includes conductor 2, wire 92, reverse polar contact 969'I, reverse winding RW, resistor RM, wire 10, and to the track rail lb, and relay HR is efiectively energized to retain its polar armature at the reverse or right-hand position and to pick up its neutral armature; As the polar armature of relay HR is reversed before the contact member 9 of contactor CI is engaged by the trolley wheel, a possible circuit, to be later described, for energizing relay N6 is opened at the normal polar contact IIli6 of relay HR. The opening of back contact 93 of relay HR extinguishes the lamp G, and the closing of front contacts 98, 99, I90 and II causes current to be supplied to the flasher relay FR, which relay is operated to alternately flash the lamps R and IR in the manner previously explained,

As this car is moving over the intersection its trolley wheel engages contact member 69 of contactor C5 to cause current to be supplied to the normal winding NW of relay HR, the circuit including contact member ,69, wire I02, reverse polar contact [93-494, winding NW, a resistor RI5, wire I9 and rail lb. The resistor RI5 and the winding NW are proportioned to provide an ampere-turn energization greater than that effected by the holding circuit energizing winding RW, and also to efiect a relatively low time constant for the circuit. The polar armature of relay HR is therefore returned to its normal position in response to the trolley wheel of the car engaging the contact member 69 of contactor C5. With relay HR restored to its normal position, its holding circuit is open at the reverse polar contact 96-9l and relay HR is deenergized to release its neutral armature subsequent to the car passing beyond the contactor C5. The lamps R and IR are now dark and the lamp G is illuminated. As this car moves to the right its trolley wheel next engages the contact member II of contactor C2, and current is supplied from conductor 2 through the contact member I I wire l2, wire I01, normal polar contact Il'l5-l06 of relay HR, wire I98, winding of relay NE, a resistor RI9, wire I0, and to the track rail I b, and the relay N6 is picked up. Relay N6 is supplied with current over a stick circuit when the contact member 5 of contactor C2 is next engaged by the trolley wheel of the car moving away from the intersection, the stick circuit involved including wires 6 and I5, front contact I25 and winding of relay N6, resistor RIG, wire I9 and rail lb. It is to be seen, therefore, that no current is supplied to relay HR when the car moves over the contactor C2 in moving away from the intersection due to the directional control effected by relay N6, the circuit to the RW winding of relay HR being open at back contact 94 of relay N6.

The operation of the apparatus for a car moving from the right to the left is correspondingly similar to that just described for the car moving from left to right. When the trolley wheel engages contact member 5 of contactor C2 current flows over wires 6 and I5, back contact 94 of relay N6, wire 95, reverse winding RW of relay HR, resistor RM, wire I9 and to rail lb, and relay HR is energized to operate its polar contact members 96, I03 and I05 to the reverse or right-hand position. The holding circuit for relay HR is now closed at reverse polar contact 95-91 so that relay HR is retained at its reverse position and its neutral armature picked up to open back contact 93 and close front contacts 98, 99, I99 and "II. The G lamp of signal S is now extinguished and flasher relay FR operated to flash the stop lights R and IR. When this car reaches the intersection and the trolley wheel engages the contact member 59 of contactor C5, current is supplied to the normal winding NW of relay HR since the circuit is closed at reverse polar contact Iil3lll4, and the polar contact members of relay HR are operated back to the normal position so that relay HR is deenergized, operation of flasher relay FR and warning indication of signal S ceases, and the G lamp is again illuminated. When the trolley wheel of this car moving from right to left engages contact member 9 of contactor CI, the directional relay N5 is picked up over the circuit including contact member 9, wires I9 and Il'I'l, normal polar contact I05-I06 of relay HR, wire Illa, winding of relay N6, resistor RIS, wire 10 and rail lb. With relay N6 picked up it is retained energized over its stick circuit while the trolley wheel engages contact member 3 of contactor Cl, and hence relay HR is not op erated as this car recedes to the right from the intersection.

It should be pointed out that in the event a car moving from left to right passes contactor CI to operate the relay HR to its reverse position and then there is a temporary failure of power to the conductor 2 while the car is between contactor Cl and the intersection, the relay HR is deenergized during the interval of power failure and the warning operation of signal S stops, but relay HR is at once reenergized and picked up over its holding circuit and the warning operation of the signal S is restored as soon as power is restored to conductor 2. A similar action for relay HR is effected in the event of a temporary loss of power while a car moving from right to left approaches the intersection.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway track intersected by a highway, a highway crossing signal at the intersection, a first pair of contact members located successively on one side of the intersection, a second pair of contact members located successively on the other side of the intersection, an additional contact member adjacent the intersection, a directional relay, a polarized relay having a normal and a reverse winding, means controlled by the member more remote from the intersection of each of said first and said second pair and including a back contact of the directional relay to supply current to said reverse winding, a holding circuit to supply current to said reverse winding including a reverse polar contact of the polarized relay, means controlled by said additional contact member and including a reverse polar contact of the polarized relay to supply current to said normal winding, a pickup circuit for said directional relay controlled by the contact member nearer the intersection of each of said first and said second pair and including a normal polar contact of the polarized relay, a stick circuit for said directional relay controlled by the contact member more remote from the intersection of each of said first and said second pair, and operating means including neutral contacts of the polarized relay to operate the signal.

2. In combination, a railway track intersected by a highway, a highway crossing signal at the intersection, a first pair of contact members located successively on one side of the intersection, a second pair of contact members located successively on the other side of the intersection, an additional contact member adjacent the intersection, a directional relay, a polarized relay having a normal and a reverse winding, a first circuit means controlled by the member more remote from the intersection of each of said first and said second pair and including a back contact of the directional relay to supply current to said reverse winding to operate the polar armature of said polarized relay to the reverse position, a holding circuit to supply current to said reverse winding including a reverse polar contact of the polarized relay to retain the polar armature at the reverse position and to pick up the neutral armature of the relay, a second circuit means controlled by said additional contact member and including a reverse polar contact of the polarized relay to supply current to said normal winding, said second circuit means eiTective to create an energization of the polarized relay that overcomes the en-ergization effected by said holding circuit and to operate the polar 1 armature to the normal position, a pick-up circuit for said directional relay controlled by the contact member nearer the intersection of each of said first and said second pair and including a normal polar contact of the polarized relay, a stick circuit for said directional relay controlled by the contact member more remote from the intersection of each of said first and said second pair, and an operating circuit for said signal including a front neutral contact of said polarized relay.

3. In combination, an electric railway provided with a propulsion current conductor and intersected by a highway, a highway crossing signal at the intersection, a first contactor located to one side of the intersection and including a pair of juxtapositioned contact members, a second contactor located at the other side of the intersection and including a pair of juxtapositioned contact members, a third contactor located at the intersection and including a single contact member, said contact members disposed to have current applied thereto by the current collector of a passing vehicle, a directional relay, a polarized relay having a normal and a reverse winding; a first circuit to connect said reverse winding between the contact member more remote from the intersection of each of said first and said second contactors and a track rail including a back contact of said directional relay and a first resistor for operating the polar armature of the polarized relay to its reverse position; a holding circuit to connect said reverse winding between said conductor and a track rail including a reverse polar contact of the polarized relay and said first resistor for picking up the neutral armature of the polarized relay, a second circuit to connect said normal winding between the contact member of said third contactor and a track rail including a reverse polar contact of the polarized relay and a second resistor, said second circuit and said holding circuit proportioned that the energization effected by the second circuit overcomes that of said holding circuit to operate the polar armature to its normal position, a pick-up circuit to connect the directional relay between the contact member nearer the intersection of each of said first and second contactors and a track rail including a normal polar contact of the polarized relay, a stick circuit to connect the directional relay between the contact member more remote from the intersection of each of said first and second contactors and a track rail, and an opening circuit for said signal including a front neutral contact of the polarized relay.

PAUL H. CRAGO. 

